Grab-bucket hoist apparatus.



PATBNTED D120. s, 19o?.

' s. H. LIBET.

lGRAB BUCKET HoIsT APPARATUS.

APPLIOATION FILED MAR` 7. 1906.

2 SHEETB-BHEBT 1.

i I lnve'nor: Sam HLib WHneSSeS @SMM/m@ .TA-K1A.

UNITED sTATE's PATENT oEEioE.

will H. L IBBY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO SPRAGUE ELECTRIC COMPANY,

A CORPORATION -OF NEW JERSEY.

GRAB- BUCKET nois'r APPARATUS.

'specification of Letters Patent. Application tiled March 7, 1906. Serial N0. 804,656.

Patented nec. 3, T907.

- To all 'whom 'it may concern:

Be it known that I, SAM H. LIBBY, a citizen of the United States, residing at East Orange, county of Essex,

5 sey, have invented certain new and useful f1 improvements in Grab-Bucket Hoist .Ap-

eraze the holding and closing ropes, and it ha;` for its object to simplify the control a paratus and to render the operation of the i5 oist convenient and certain.

It has been pro osed to provide hoists of .this character witii two motors, one for the .holding rope and one for the closing or hoisting rope, together with a controller for gov- 2.0 erning the operation of the motors; the controller being so arranged that .both motors are set in operation to pay outytheir respective ropes upon lowering the bucket and to wind up the ropes in hoisting the bucket, the

z5 closing motor being started somewhat ahead of the other motorin order [to close the bucketl and cause -it to take upia quantity of the material to be handled. With this arrangement it is evident that skilful manipulation of the controller is necessary in order that the two ropes shall not be unwound after the bucket has been dropped upon the material, since otherwiseit willl be ossible for the slack ropes to be entangled with each other as well as with the parts ofthe apparatus'. Similarly, in closing the bucket care must be exercised in order that no slack may be formed in the holding ro e through a lifting of the bucket before the l in operation. Not only is fouling of the ropes apt to occur, but the motors may acquire considerable momentum before assuming their loads in case the ropes are slack and thus produce objectionable jarring and jerking in the apparatus.

he present invention contemplates 4a system of control for the holding and closing ropes such that the objections above noted are practically obviated, since the attention which is required on the part of the operator is reducedto a minimum and'therefore the danger of the formation of slack is reduced proportionately. To this end I arrange the control apparatus so that both motors are started simultaneously when it is desired to ing motor;

olding motor is set t l an' operators platform close the bucket, and make the motor for the holding rope of a size sufficient only to vmaintain the holding rope taut or else insert sufficientresistance in its circuit during the Y closing operation to cut down this power vat that time. The holding motor is never reversed, even to allow the bucket to descend, but during the descending movement of the bucket the holdin the drag of a loadr e',vthe' paying out o eration of course ceasing as soon as tfie bucket drops upon the material to be moved. Thus the only time when slack may form in either rope is during the dropping of the bucket uplon the material to -be moved, and then, if t e closing motor is not just the right instant, some slack may be formed iii the closing rope but in thatrope alone. The difficulties ex erienced in rior arrangements due to slac in the ho din rope are therefore entirely eliminated an but little care need be exercised by the o erator to avoid difficulties on account o the closing rope.

The present invention 4in its various aspects will be fully understood and its objects and advantages will more clearly appear from the following'description thereof taken in connection with the accompanying drawings Wherein:

Figure 1 is an end elevation of a carrier adapted to move along an elevated track and provided with my improved hoisting apparatus; Fig. 2' is a side elevation of the mechanismfshown in Fig. l; Figs. 3 and 4 are details illustrating the load-brake for the hold- Fig. 5 is a diagram showing the two motors together with the main controller and connections; and Figs. 6 to 9, inclusive, are diagrams indicating the conditions of the motor and braking circuits during the several operations of closing, raising, dumping and lowering the bucket.

lReferring to Figs. 1 to 4, A represents a grab-bucket of the usual clam-shell type suspended from a traveling carrier B by holding and closing ropes 1 and 2, respectively; these ropes being operated by electric motors 5 and 6. 7 is a controller for governing the operation of the two motors. This controller may be located in any desired position, as, for example, upon 8 secured to the carriage. 9 is a traverse motor for propelling the'carriage along the track 10 in order to rope is paid out againststopped at i mounted upon drums 3 and 4 2 872,523 convey the bucket from one point to an- I are illustrated as series motors and the motor other. urrent for the severalv motors is ob-., 5 as being smaller than the other' motor but tained from trolley wires 11 and 1 2 through l capab'leo .assisting it in lifting the/load. current collecting devices 13 and 14 mounted In closing the bucket the power of the small 5 upon the carriage. vThese parts, except to `inotorasaholdinginotoris cut down through the extent hereinafter indicated, may all the insertion of 'a resistance 5 in seiies take any usual or preferred forms, the partherewith lhe motors inay or course be ticular forms shown being simply illustraof any type or types. For sake of simplicity, tive of a general type of apparatus to which j the controller 7 is indicated as aving only t e present invention nia be applied. Fur` 'four running positions and an ed posieimore, it is evident that the hoisting aption. In the off position ot the controller paratus may be otherwise -supported or carall the ciiciuts aie interrupted and the brakes ried than upon a carriage moving along a l' 16 and 26 associated with the motors 5 and track. 6, respectively, are applied. pon moving l5 In Figs. 3 and 4, 15 represents the arnial the controller to the lirst running position', ture of the holding motor, and- 16 the usual l circuits may be traced from the current col` .brake associated with t e-arinature shaft. lector 14a as follows: through contacts 27, second brake 17 is applied to the vinotor 28, 29 and 30 of the controller, through the armature for maintaining the holding rope releasing coil of the brake 16, to the ret-urn taut in lowering the ucket This latter circuit,-here indicated as a ground circuit. rake consists oi a disr 18 loosely mounted second circuit passes thi ouch controller upon the armature shalt and arranged becontacts 27, 28, 31 and 32, through the windtween a fixed collar 19 and a sliding collar P0 ings ol. the inotor5, through resistance The disk is yieldingly gripped between these controller contacts 36, 37, 38 and 39, to the two collars by reason of the action of a s ring return circuit. n A furt ier cii cuit may be I 1 arranged between the sliding collar 2() and traced through controller contacts )7, 28, the shouldr'22 on the shaft. A lockingde` 33 and 34 to the armature or the inotor 6, vice consisting of an inclined plane 23 and a I through controller contacts40 41 42 and 43 ball or roller -24 arrangedbetween the intirough the iield windinU of the motor 6, clined plane and the periphery'of the disk controller contacts 44, 45, 46, 47, through 18, serves to hold the disk stationary when the releasing coil of the brake 26 to the iD e motor is turned in the direction to pay urn circuit. liese connections are indiout the holding rope, but permits the disk to cated in Fig 6 and it will be seen that both rotate freely in the opposite direction. IThus of the electromagnetic brakes are released it will be seen that when thejmotor is operand bot i motors are energized so as to tend ated to wind up the cable, the auxiliar to wind up th ir respective I"opes Tins is brake mechanism has no eflect,since the disk l t ie condition of t e circuits when the bucket 18 revolves freely with the motor. If, hou`- is bein(T closed, the motor 6 producinfr the ever, the motor remains deenergized and the c osin(r effort and the inotor 5, w ose power 40 ho ding rope is unwound due to the weight is reduced by means oi resistance 5 exei ts of the descending bucket, the motor arinaenough influence only to inaintaiirthe holdture is rotated in the oppositedirection: disk ing rope taut. In t e second positicn'of the 18 is heldstationary and a braking action is controller the circuit conditions reiiiainnni set up between the dislr and the two`collars l changed except that resistance 25 is cut out on the armature shaft dependent in amount of tie circuit of the noldinO motor and the removed, -upon the material to be moved, the rope instantly ceases.

may be conven upon the t rope suflicientl i buc iet without unduly retarding the movement of the' bucket itself. as soon as the by reason of the bucket dropping unwinding of the holding While the auxiliary brake iently applied to the armature shaft of the l, since it is onlvnecessar f that it be so ing influence direction'but other.

not in the controller connections.

ln Fig. 5 I have illustrated the motor and lhe motors 5 and 6 ing motor it is or course understood that the particular location of this brake is iinma-vll v l s othat tlie-helchng rope is locked against 1 controller contacts 35, 35., 38 and 39. is the position to which inoved after the bucket has hol 'iig motor now assisting the other inotor in raising'the load. vVlhen it is desired to dump the the -thi d tirely .releasing coil of theY brake 16 is interrupted un'winding. The Vconnection of the field of y tlie'closingmotor tothe armature `yin this position of the controller by contacts 49, 50, 51 and 52, so that the'closing motor .unwinds the closing 'rope and permits the bucket, the controller isnioved to positionand, since there the cont-rollerlis been closed, the.

is reversed .bucket to open.

is now supplied tothe releasing coil oi' ther The circuit connections dumping operation are indicated in Fig. 8. After the bucket has been brought above the material to be moved, it may again be lowered upon the material by moving the controller to the Jfourth running po'- sition.- 'No further changes in the circuit connections are produced except that current during the brake-16 through contacts 27, 28, 53, and 3Q of the controller. for this position of the controller are indi# cated in Fig. 9. It will be seen that now the brake which locks the holding rope against movement is released and the holding rope may be unwound through the action ,of the bucket'in descending. `During this 'operatien, however,v the 'iolding rope does not unwindv freely-but is retarded by the loadbrake 17 which maintains the rope taut and 'causes the unwinding thereof to cease immediately upon the removal of the unwinding pull, namely, as "soon as the bucket reaches the material to be moved.

Although I have described the present invention in detail as carried out inpone embodiment, I do not desire to be limited to the articular embodiment illustrated, since in its broader aspects; namely, those relating to' the simultaneous energization of both motors, and maintenance of the holding rope taut at all times, the present invention may beeinbodied in various other forms, and in the ap. pended claims I intend `covering all suchforms in addition to thatiillustrated. C

What'I claim as new and desire to secure i by Letters Patent of the United States, isfv 1. In-,a grab-bucket hoist, a bucket, a holding rope and a closing ro e-motoi's for Vo erating said ropes, a control er for causing ,t e motor for the closing rope to operate in ,elther direction and for causing the motor y for the holding rope to operate only 4to wind upthat rope, and meansv for applying tension to the holding rope while the bucket is being lowered.

2. Inv a grab-bucket hoist, a bucket, a holding rope and a closing rope, motors for 'operating said ropes, means for vcausing the motor for the closing ro e to wind up the closing rope ,in raising. t e bucket and unwind the closing rope in lowering the bucket and for causing the motor for the holding rope to operate only to wind up the rope, and

means for paying out the holding rope under tension in lowering the bucket.

3. In a grab-bucket hoist, a bucket, a holding rope and a closing `rope connected to said bucket, motors connected to said ropes for operating the saine, and means for simultaneously energizing the motor connectedI to the closing rope to close tli'e bucket and supplying the motor connected to the holding rope with only suliicient current to maintain the holding rope taut.

The circuit connections 4. In a grab-bucket hoist, a. bucket, a .holding rope and a closing rope, motors for operating said ropes, and means for simultaneously energizing the motor connected to the closing rope to close the bucket and sup plying the' motor for the" holding rope with ing rope taut and. for then increasing the power of the motor for the holding rope to ,assist the other motor in raising the bucket.

5. In a grab-bucket hoist,` a bucket, a holding rope and a closing rope, a motor for said closing rope, a motor for said holding rope, a controller for said motors, a brake for maintaining said holding rope stationary in dumping the bucket, vand an auxiliary brake device for applying ltension to said holding rope while the bucket is being lowered.

. 6. In a grab-bucket hoist, a bucket, a holding rope and a closing rope, a motor for operating said closing rope, a motor for said holding rope, a brake for maintaining said .holding rope stationary in dumping the bucket, and a brake device for permitting said holding rope to unwind under tensionin lowering the bucket.

7. In a grab-bucket hoist, a bucket, a holding` rope and a closing rope, motors for operating said ropes, and an automatic brake device for permitting the holding rope to move freely in one direction and holding it under a tension when moving in the opposite direction.

8. In .a grab-bucket hoist, a bucket, a holding--rope anda closingv rope, motors for operating said ropes,`ineans for energizing both motors in a direction to wind up said ropes to raise the bucket and to energize one of the motors to unwind the closing rope only to lower the bucket, and means for paying kout thev holding rope under tension in lowering the bucket.

9. In aA grab-bucket hoist, a bucket, a holding rope and a closing rope, motors for operating said ropes, a controller for said motors, an electro-inagnetically-controlled brake associated with said holding rope, contacts on said controller for causing the aforesaid brake to be applied and the inotor for the closing rope energized in a direction to unwindthe closing rope in dumping the bucket, and a load-brake operatingl to retard the unwinding of the holding rope in lowering the bucket.

holding rope anda closing rope, motors for operating said. ropes, electrically controlled brakes Jfor said motors, and a controller for causing said hoisting motor to operate in either direct-ion, for causing said holding motor to o crate only in a hoisting -direction, uand or controlling the operation ot said brakes l1.` In a grab-bucket hoist, a bucket, a holding rope and a closirigrope, motors for only sutiicient current to maintain the hold-` 10. In a grab-bucket hoist, a bucket,

llO

operating said ropes., electricall` brakes for said motors, a controller for eausing said hoisting motor o operate in either dlrectlon,

and a controller, for controllingtion of said hoistin A l tions, for controlling holding motor Y' in or cutting out the reslstance in its circuit,

/ and for controlling the operation of the braking devices.

Y controlled l d o i Witness whereof, I have hereunto set I ing of the bucke my hand this twenty third day of February,

l2. n a grab-bucket hoist, a bucket, a 1906.

SAM' H. LIBBY.

e. closnig rope, motors 'or l operating said ropes, electrically o erated Witnesses:' ra les for sald motors, a resista-nce or cut- ROGER H. BUTTERWORTH, tuig down the power of said holding motor, I ANNA M, GILLIN. 

